At present, typical voltage reference circuits can only generate a temperature independent (TI), band-gap (BG) voltage reference having a magnitude of about 1.2 V. When another voltage value is desired or required, usually a resistor ladder which raises or lowers the band-gap reference voltage, is used to generate it; but, because resistors have a positive temperature coefficient, the generated voltage is not a TI reference voltage.
Accordingly, there is a need for a circuit that can generate temperature independent BG voltage references and any other value voltage references that are independent of the effects of temperature.
It is therefore an object of the present invention to provide a voltage reference circuit that can be used to generate various selected reference voltage values with temperature independence.